---
name: "Test2::Manual::Tooling::Plugin::ToolStarts"
section: "3p"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/Test2::Manual::Tooling::Plugin::ToolStarts"
---

# Test2::Manual::Tooling::Plugin::ToolStarts(3p)

How to add behaviors that occur when a tool starts work.

## NAME

Test2::Manual::Tooling::Plugin::ToolStarts - How to add behaviors that occur when a tool starts work.

## DESCRIPTION

This tutorial will help you write plugins that have behavior when a tool starts. All tools should start by acquiring a context object. This tutorial shows you the hooks you can use to take advantage of the context acquisition.

## COMPLETE CODE UP FRONT

```
    package Test2::Plugin::MyPlugin;
    use Test2::API qw{
        test2_add_callback_context_init
        test2_add_callback_context_acquire
    };
    sub import {
        my $class = shift;
        # Let us know every time a tool requests a context, and give us a
        # chance to modify the parameters before we find it.
        test2_add_callback_context_acquire(sub {
            my $params_ref = shift;
            print "A tool has requested the context\n";
        });
        # Callback every time a new context is created, not called if an
        # existing context is found.
        test2_add_callback_context_init(sub {
            my $ctx_ref = shift;
            print "A new context was created\n";
        });
    }
    1;
```

## LINE BY LINE

- use Test2::API qw{test2\_add\_callback\_context\_init test2\_add\_callback\_context\_acquire};

  This imports the `test2_add_callback_context_init()` and `test2_add_callback_context_acquire()` callbacks.

- test2\_add\_callback\_context\_acquire(sub { ... })

  This is where we add our callback for context acquisition. Every time `Test2::API::context()` is called the callback will be run.

- my $params\_ref = shift

  In the **test2\_add\_callback\_context\_acquire()** callbacks we get exactly 1 argument, a reference to the parameters that `context()` will use to find the context.

- print "A tool has requested the context\\n"

  Print a notification whenever a tool asks for a context.

- test2\_add\_callback\_context\_init(sub { ... })

  Add our context init callback. These callbacks are triggered whenever a completely new context is created. This is not called if an existing context is found. In short this only fires off for the top level tool, not nested tools.

- my $ctx\_ref = shift

  The coderefs for **test2\_add\_callback\_context\_init()** will receive exactly 1 argument, the newly created context.

- print "A new context was created\\n"

  Print a notification whenever a new context is created.

## SEE ALSO

Test2::Manual - Primary index of the manual.

## SOURCE

The source code repository for Test2-Manual can be found at *https://github.com/Test-More/test-more/*.

## MAINTAINERS

- Chad Granum \<exodist@cpan.org\>

  ## AUTHORS

- Chad Granum \<exodist@cpan.org\>

  ## COPYRIGHT

Copyright Chad Granum \<exodist@cpan.org\>.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

See *http://dev.perl.org/licenses/*